Abstract Particle deposition in the human respiratory tract is considered to have negative effects on human health. The lung deposited surface area (LDSA) is an important metric developed to assess the negative health effects of particles deposited in the alveolar region of the human respiratory tract. The measurement of the LDSA is frequently based on the detection of the electrical current carried by diffusion charged particles. Various conversion factors can be used to convert the electric current into LDSA concentration with relatively good accuracy up to the size about 300-600 nm. In this study, we introduce stage-specific LDSA conversion factors for electrical low pressure impactor (ELPI+) data, which enable accurate and real time LDSA concentration and LDSA size distribution measurements in the particle size range from 6 nm to 10 µm. This wide size range covers most of the alveolar deposition of particles, which has not been possible previously by electrical methods. Also, the conversion factors for tracheobronchial and head airways particle surface area deposition were determined, and the stage-specific conversion factors were compared with the single-factor data conversion method. Furthermore, the stage-specific calibration was tested against real-world particle size distributions by simulations and against laboratory-generated aerosols. Particles larger than 300 nm were observed to significantly affect the total LDSA concentration. Stage-specific conversion factors are especially required while measuring aerosols containing larger particles or when considering the surface area deposition in the tracheobronchial region and head airways. The method and the conversion factors introduced in this study can be used to monitor LDSA concentrations reliably in various environments containing particles in different size ranges. Copyright © 2020 American Association for Aerosol Research

中文翻译：

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用电动低压撞击器测量人体呼吸道沉积颗粒的表面积

摘要 人体呼吸道中的颗粒物沉积被认为对人体健康有负面影响。肺沉积表面积 (LDSA) 是一项重要指标，用于评估沉积在人体呼吸道肺泡区域的颗粒对健康的负面影响。LDSA 的测量通常基于对扩散带电粒子携带的电流的检测。可以使用各种转换因子将电流转换为具有较好精度的LDSA浓度，最大尺寸可达约300-600 nm。在本研究中，我们为电动低压冲击器 (ELPI+) 数据引入了阶段特定的 LDSA 转换因子，从而能够在 6 nm 到 10 µm 的粒径范围内实现准确和实时的 LDSA 浓度和 LDSA 粒度分布测量。这种广泛的尺寸范围涵盖了颗粒的大部分肺泡沉积，这是以前通过电方法无法实现的。此外，确定了气管支气管和头部气道颗粒表面积沉积的转换因子，并将特定阶段的转换因子与单因子数据转换方法进行了比较。此外，通过模拟和实验室产生的气溶胶，针对真实世界的粒度分布对阶段特定的校准进行了测试。观察到大于 300 nm 的颗粒显着影响总 LDSA 浓度。在测量含有较大颗粒的气溶胶或考虑气管支气管区域和头部气道中的表面积沉积时，特别需要阶段特定的转换因子。本研究中介绍的方法和转换因子可用于在包含不同尺寸范围的颗粒的各种环境中可靠地监测 LDSA 浓度。版权所有 © 2020 美国气溶胶研究协会